首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   153篇
  免费   1篇
化学工业   6篇
金属工艺   1篇
建筑科学   6篇
能源动力   2篇
轻工业   9篇
无线电   2篇
一般工业技术   2篇
冶金工业   123篇
原子能技术   3篇
  2021年   1篇
  2020年   1篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2013年   6篇
  2011年   1篇
  2009年   2篇
  2008年   2篇
  2007年   2篇
  2005年   2篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  1999年   5篇
  1998年   32篇
  1997年   19篇
  1996年   13篇
  1995年   6篇
  1994年   3篇
  1993年   6篇
  1992年   1篇
  1991年   6篇
  1990年   6篇
  1989年   6篇
  1987年   1篇
  1986年   3篇
  1984年   1篇
  1982年   2篇
  1981年   1篇
  1978年   2篇
  1977年   3篇
  1976年   13篇
排序方式: 共有154条查询结果,搜索用时 0 毫秒
21.
22.
The present study was performed to evaluate local tumor control and side effects of endoluminal radiotherapy given to patients with rectal tumors. Twelve patients with adenocarcinoma and 10 patients with villous/adenovillous adenomas were treated with curative intent from 1989 to 1995. The majority of patients were of advanced age and in poor medical condition, and had previously been found unable to undergo radical surgery or colostomy. Three patients had tumor remains following radiotherapy, they successfully received local surgery (n = 2) or an iridium implant (n = 1) as second-line treatment. Two patients (adenomas) later experienced a local relapse. No serious side effects were observed. We conclude that endoluminal radiotherapy is an efficacious option for patients with malignant or premalignant tumors in the lower rectum who are in poor medical condition.  相似文献   
23.
24.
Spirometric, gasometric and electrocardiogarphic studies were carried out in 17 patients at rest, who were treated surgically for extreme obesity (overweight from 52 to 175 per cent in relation to the normal weight). The measurements were made before operation. It was found that the mean spirometric values were within the range of acceptable deviations from the normal value. The residual volume showed a tendency towards decreasing, especially in young patients. The values of dynamic parameters indicated a tendency towards ventilatory changes of a restrictive type in both groups. Minute ventilation at rest increased proportionally to obesity. Decreased values of respiratory equivalent indicated a good economy of respiration in obese persons when at rest. The mean gasometric values in capillary blood at rest were also within the acceptable range of abnormalities. Electrocardiographic tracings taken at rest showed considerable changes in the group of more obese persons.  相似文献   
25.
Epidermal infiltration by neoplastic CD4+ T cells is a characteristic histologic feature of early stage mycosis fungoides, the most common type of cutaneous T cell lymphoma (CTCL). The mechanisms involved in epidermotropism are unknown. It has been suggested that the CXC chemokines IL-8 and interferon-gamma inducible protein 10 (IP-10) may play a role, but evidence that these chemokines are produced within the epidermis in epidermotropic CTCL is lacking. In this study skin biopsies from 17 CTCL patients, including 12 mycosis fungoides, four pleomorphic CTCL, and one CD8+ CTCL, were investigated for epidermal IL-8 and IP-10 mRNA expression by RNA in situ hybridization. In addition, the expression of monokine induced by gamma-interferon (Mig) mRNA, a CXC chemokine closely related to IP-10, was studied as well. The expression of IL-8 receptors A and B (CXCR1 and CXCR2, respectively) was investigated by immunohistochemistry. The results were correlated with the number and phenotype of epidermotropic T cells. Epidermal expression of IP-10 and Mig mRNA was detected in 10 of 11 and seven of 11 epidermotropic CTCL, respectively, but not in five nonepidermotropic CTCL biopsies or normal human skin. Epidermal IP-10 and Mig mRNA expression correlated with epidermal infiltration of CD4+ T cells, but not of CD8+ T cells. IL-8 mRNA was demonstrated in the epidermis of only two of 15 CTCL biopsies, and was associated, in both cases, with accumulation of neutrophils. Consistently, immunostaining of the (intraepidermal) T cells with antibodies against CXCR1 and CXCR2 was not observed. In conclusion, the results of this study indicate that IP-10, and to a lesser extent Mig, but not IL-8 is involved in the preferential infiltration of neoplastic CD4+ T cells in CTCL.  相似文献   
26.
A non-thermal, atmospheric pressure, packed-bed plasma reactor has been used to study the effect of temperature on the plasma-catalytic destruction of toluene and benzene in air using two catalyst positions. TiO2 and γ-Al2O3 supports, and Ag (0.5 wt.%) impregnated catalysts of both supports, were used to determine their effects. The reactor (in the one-stage configuration) or the downstream catalyst (in the two-stage arrangement) could be heated to 600 °C and the destruction efficiencies for toluene and benzene were determined. Plasma catalysis is more effective at destroying benzene and toluene than both conventional thermal-catalysis and plasma alone. Toluene is destroyed much more efficiently than benzene, regardless of the temperature of the system and the reactor configuration. A one-stage, plasma-catalysis configuration is found to be more effective at destroying both toluene and benzene than a two-stage configuration. Plasma catalysis offers no advantage over thermal catalysis for destroying both pollutants in the two-stage configuration.  相似文献   
27.
The effects of in utero cocaine exposure on the development of the mRNAs encoding the dopamine transporter (DAT) and the D1, D2 and D5 dopamine receptor subtypes were determined in fetal monkey brains at day 45 and day 60 of gestation. Pregnant monkeys were treated with cocaine 3 mg/kg or saline i.m., four times a day from day 18 of gestation until the pregnancy was terminated at day 45 or day 60. The fetal brains were dissected, and tissue RNA extracted and quantified using ribonuclease protection assay analysis. In day 45 fetal monkeys, dopamine D1 and D2 receptor subtype mRNAs and DAT mRNA were found in low quantities both in control and cocaine-treated subjects. In day 60 fetal monkeys, D1 receptor mRNA levels were highest in the frontal cortex/striatal area, and low to moderate quantities were found in diencephalic and mesencephalic fetal brain regions. Dopamine D2 receptor mRNA levels were highest in the frontal cortex/striatal area, diencephalon and the midbrain, moderate in the brainstem and low in the caudal temporal lobe and surrounding cortical areas. Dopamine D5 receptor mRNA was expressed in low quantities throughout the day 60 fetal monkey brain, whereas DAT mRNA was found in the midbrain only. In utero cocaine exposure caused a significant increase in dopamine D1, D2 and D5 receptor subtype mRNAs in the frontal cortex/striatal area of day 60 fetal monkeys. These results support the hypothesis that dopamine synthesis and release may be reduced in cocaine-treated fetuses, which results in dopamine receptor up-regulation.  相似文献   
28.
29.
This paper is based on a one-year ethnographic study that focused on nurse-patient relationships on a ward where therapeutic nursing and professional autonomy were explicit nursing goals. Through participant observation and semi-structured interviews, it was found that nurses, as a team, adopted a highly relaxed form of posture. Their informal and open stance served to emphasize their 'closeness' with patients, supporting nurses' claim of a special role in the healthcare team, and making flesh some of the differences between nursing and medical roles. The interpretation of nurses' bodily practice rested in part on the meanings given to the ward space patients felt the ward to be a private domain in which nurses' informality endorsed their sense of being cared for as if by family, while for medical staff the ward remained a public space in which female nurses tacitly challenged their authority as men through the adoption of a masculine bodily praxis. The paper thus looks at links between the gendered body, the gendered professions of medicine and nursing, and the gendered nature of space. It argues that work on occupational closure has previously privileged the discursive, and suggests that understanding how nurses arbitrate professional boundaries in everyday practice will benefit from consideration of the nurse's body as a point of political resistance.  相似文献   
30.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号